Method of manufacturing tubular bags, envelopes, and like containers with folded bottoms



J. W. RANDALL Feb. 12, 1957 AND METHOD OF' MANUFACTURING TUBULARBAGS, ENVELOPES,

LIKE CONTAINERS WITH FOLDED BOTTOMS Filed June 17, A1952 lVlETHGI) F NIANUFACTURING TUBULAR BAGS, ENVELGPES, AND LIKE CONTAINERS WITH FOLDED BTTMS lohn William Randall, Hemel Hempstead, England, assignor to John Dicln'nson C0.,\Limited, Hemel Hempstead, England, a British company Application June 17, 1952,'Se1'ia1 No. 294,105

Claims priority, application Great Britain June 20, 1951 Claims. (Cl.'93-35) The present inventionrelatesV tothe manufacture of bags, envelopes'andthe'like containers, hereinafterreferred to as bags, from paper, celiulosic and other flexible sheet materials suitable'for'the purpose, vand yis applicable with considerable advantage,:altho ugh not restricted,'to the manufacture of bags'from machine made bag tubes formed from continuous webs ofibag-making material.

Bags formed by folding roverfone end of a bag tube of suitable length andfsecuring the inturned face of the fold to the external wall of the'bag tubeand securing the opposed meeting faccsfof thefolds together (when two or more bottom` folder-are formed) .are satisfactory in use for many purposes but are notproperly powderproof. rIhus, finelyV granular powdersy and like substances tend to work around and `-between'the bottom Vfolds of such bags, particularly at'the ycorners or ears of the. folds, so forcing the folds apartand leventually bursting the bags in addition to leaking therefrom.

ln order to overcome the above lmentioned disadvantage, in manufacturing bags with double-foldbottoms Apro duced by forming a bag tube froma Vweb of materialand then twice folding over the bottom Vend -of a tubular bag length severed therefrom, ithaspreviously been proposed to apply transverse stripes'ofadhesive to the inner face of the web, prior kto formingthe bag tubeftherefrom, so that the inner walls .of eachtubular Ibag length severed from the bagtube'formedl from the web are united by a single stripe of adhesiveextending across the entire width thereof at the placeintended to become the folded bottom of the bag, and then to apply two stripes of adhesive to-theiexternal wallfof the severed tubular bag length in the region-'of thev bottom end folds thereof, in order to ensure that thetwo bottom end folds, when made, are secured to the external wall of the bag tube and to each other.

PThe primary object of the present invention Ais to'provide Va modified/'and improvedfmethod -of producing tubular bags with bottom folds lwhich do not tend to unroll when iilled and 4anotherobject of the Yinvention `is toproduce modied and improved formsof tubular bags with substantially powderproof bottom'folds.

According to the present inventiomprovision is made of a method of producing a tubular bag with a folded bottom comprising the steps of forming a-bag tube with an opening in the bottornend fold area of lone of its sides through which the -internal'wall of the opposite side of the bag tube is exposed-across substantially its entire width, applying adhesive to the formed bag tube in the bottom end fold area thereof so that'the adhesive extends across the bagtube Aand at least in` part in contact with the internal wall ofthe bag tube along the entire length of the opening through which the internal wall is exposed, and then `'transversely folding the bottom end of the bag tube so that the adhesive -lies beneath the bottom fold and secures 'the inturned face of the said bottom fold to both the internal and externall walls of the baU tube thereby to seal` the bottomend yfold of ied States Patent 2,780,969 Patented Feb. 12, l1957 ice bag tube along the entire length of Ythe transverse edge of the opening so formed in the bottom end fold area and in overlapping relation thereto, so -that the adhesive is applied in part to the external-Welland in part'to ythe exposed internal wall of the -bag tube, and the bottom end of the bag tube is then transversely folded over the said opening so that the inturned face Aofthe-*bottom fold contacts the adhesiveY and is secured therebyfto -both the internal and external walls ofthe bagtube thereby to seal the end fold of the rbagacrossl substantially 'the entire width thereof.

In another manner of carrying vthemethod ofv this `invention into effect, an adhesive stripe is vapplied to'that part of the bottom end of the bag tube'which formsthe inturned face of the bottom end fold flap, .so 'that the adhesive stripe is brought into Contact fwiththeexternal--wall and exposed internal wall of the bag'tube Aalongthe entire 4length of the said opening inthe bottom end fold area of the bag tube lwhen'the bottom end-fold is formed.

The method above set forth may also include the step of cutting away a portion of each longitudinal margin of a bag blank or Aweb from which the bag tube is to be made so that when the 'bag tube is formed vby folding the longitudinal margins of the blank or web inwards in overlapping relation across *r'hefcentre4 part thereof, the openings left by the cut away portionsareA combined to form the transversely extending openingin the bagV tube side wall through which the internal wall'of the opposite side thereof is exposed.

if the tubular' bag kformed as above described is to vbe provided with a'second end fold or two or more subsequent end folds, atleast one additional 'stripe ofadhesive willbe applied to the external wall of the' .formedbag tube in the end fold area thereoiprior .to completing the said second'fold or subsequent folds, lor to the external face of the first formed end'foldor subsequentv fold, in order to secure the said second endfold andv subsequent end fold or folds, when made, to Lthe, wall of the .bag tube.

The method of this'iuvention is equally applicable to the manufacture of plain -or`iiatl bags with singlefold or multifold bottoms or gusset sided or Satchel bags with single fold or multi-fold bottoms and' lends itself, with considerable advantage to the production of .either flat or- Satchel bags with scalloped mouths.

Both'ilat and sat'chel'bags produced by the method of this invention are rendered substantially powderproof for the reason that the foldedbottoms of thebags,

including the corners or -ears thereof, are substantially completely sealed'by the adhesive which secures 'the bottom end fold flaps to the internal andrexternal walls of the bags across the entire width thereof.

Modes of carrying the method of this invention linto effect, more particularly as applied -to the production of gusset folded Satchel bags with-double folded bottoms from a continuously formed machine made bag tube will hereinafter be further described, by -wayof example and without implied limitation of the scope of the invention, with reference to the accompanying purelydiagrammatic drawings in which:-

Fig. l shows,'in topplan view, vthe successive'stages-of forming a web of paper-or other suitable bag-making material into a continuous bag tube with longitudinal gusset folds and cut-away Abottom end fold areas and'rob- Vtaining tubular bag lengths therefromfor ythe production .drawn to a ylarger scale,rshowingfthe successive-stagesof forming a gusset-sidedfor--s'atchel bagY of tubular-.formation with a double fold substantially powderproof bottom;

Figs. 6-9 are greatly exaggerated fragmentary cross -sectional views of the bottom end fold areas and folds of the tubular bag lengths shown in Figs. 2-5 respectively;

Fig. l is a fragmentary plan view, drawn to ya larger scale, to show in detail the disposition of the adhesive stripes applied to the bottom end fold area of the tubular bag length;

Fig. 1l is a fragmentary plan view, showing in detail an alternative disposition of the adhesive stripes applied to the bottom end fold area of the tubular bag length, and

Fig. 12 is a fragmentary plan View showing in detail another alternative disposition of the second adhesive stripe Whichis utilised to secure the second bottom fold to the external wall of the tubular bag length.

Referring to Fig. 1 of the drawings, a web of paper or other suitable bag-making material 1 may be fed from a I supply reel to the gusset-fold forming means and bagtube forming means of any suitable form of tubular bagforming machine. In travelling tothe first gussetfold forming means the web 1 receives adhesive from a first adhesive-applying station having means for applying the usual longitudinal seaming stripes of adhesive 2 to the inner face of one longitudinal margin of the web, for securing together the overlapping-longitudinal `fold aps 3 of the bag tube formed from the web, and means for applying transverse stripes or patches of adhesive 4 to the inner face of the web in the rst gusset fold areas thereof, in order to seal the Walls of the aforesaid first gusset folds internally, when made, in the bottom end fold areas of the tubular bags subsequently produced from the formed bag tube.

The adhesive-treated web may thereafter be engaged by suitable fu'st gusset-fold forming means which serve to tuck in the longitudinal marginal portions of the web to form the rst gusset folds 5 therein.

Portions are removed from each longitudinal fold edge Y of the web, either before or, as shown after the first gusset folds are made, to provide slots or notches 6 oppositely aligned and extending inwards almost to the full depth of the rst gusset folds 5 and disposed so as to extend to each side of the transverse severing line 7 along which the tubular bag lengths 8 are subsequently severed from the continuous bag tube 9.

The web 1 is thereafter engaged in final gusset-fold forming means which complete the longitudinal gusset folds and infold the longitudinal margins or flaps 3 of the web into overlapping relation for securing together by the previously applied longitudinal searning stripes of adhesive 2, thereby forming the bag tube 9. In this operation, the oppositely aligned marginal slots or notches 6 are brought together with the open ends thereof in register to form elongated,k e. g. substantially oval, slotlike openings 10 of appreciable Width through which some part of the Vinternal wall 9a of the opposite side of the bag tube and final gusset fold walls 5a are exposed.

The bag tube thus formed is then passed to a second adhesive-applying station to receive transverse stripes of adhesive 12 applied externally across the overlapping longitudinally extending fold aps 3 so that some part of each adhesive stripe 12 overlaps the longitudinal edge 13V of the transverse slot-like opening 1t) and is applied to some part of the internal wall 9a of the opposite bag tube side and final gusset fold walls 5a exposed therethrough, the adhesive being conned to the bottom end fold area of each bag length as defined by the transverse severing lines 7 along which the tubular bag lengths are subsequently severed from the bag tube.

The transverse adhesive stripes 12 extend across the entire Width of the sides of the formed bag tube 9, i. e. to the longitudinal fold lines thereof, and may also extend to the rst transverse'fold line of the bottom'` fold ap, or space may be left between the bottom fold line and lower edge of the adhesive stripe to allow the tucker blade of the bottom fold forming means to operate without contact with the adhesive.

The bag tube 9 is then severed along the severing lines 7 intersecting the transverse slot-like openings 10 lengthwise so that each tubular bag length B (see Fig. 2) thus separated from the continuously formedy bag tube has each end of one of its sides scalloped while the ends of the opposite side of the bag length extend as a bottom flap 14 and mouth liap 15 respectively from the opposite scalloped ends thereof. The mouth end, and flap 15 extending therefrom, of each tubular bag length 8 thus severed from the bag tube 9 are entirely clear from the transversely applied adhesive, While the other end of the bag length, i. e. the bottom fold end, carries the transversely applied stripes of adhesive 12 for contact with thebottom fold end flap 14 which is sufficiently deep to cover the said slot-like opening and lap over the edge of the latter into contact with the external Wall of the bag length when infolded about the first transverse bottom fold line 16 of the bag tube (see Figs. 6 and 10).

The tubular bag length is then progressed to rst bottom fold forming means and the rst bottom fold made by infolding the bottom end flap 14 about the first bottom fold line 16 (as shown in Figs. 3 and 7), thus bringing the inturned face of the fold flap into contact with the adhesive stripe 12 which thereupon secures the foldflap to the external Wall 9b of the bag side formed by the longitudinal fold aps 3 and to the exposed portion of the further or opposite internal wall 9a and nal gusset fold Walls 5a of the bag so formed, thus effecting an internal and external'sealing of the bag bottom and completing the internal sealing of the gusset folds which are, in part, sealed by the adhesive patches 4.

Alternatively, or in addition, to applying the bottom end fold-securing adhesive stripes 12 to the external and internal walls of the tubular bag lengths in the vicinity of the .slot-like openings 10 .as above described, the adhesive in at least one transverse stripe may be applied, as shown in Fig. l1, to that face of the bottom end fold ap 14 which is subsequently inturned to cover the said opening 10` when the first bottom end fold is made. The adhesive thus carried by the bottom end fold ap will be brought into contact with the external wall 9b and exposed internal Walls 9a of the bag tube and iinal gusset folds 5a, or with the adhesive already applied thereto, when the rst bottom fold is made.

The inturned face of the said bottom end fold and fold ap 14 may be coated with adhesive extending to the bottom fold line 16 thereof, or, as shown, a clear space may be left between the bottom edge of the adhesive and bottom fold line for the purpose set forth above.

The tubular bag length with its bottom end once folded is then forwarded to another adhesive-applying station to receive a further stripe or stripes of adhesive 17 applied across the Wall of the bag in the area covered by the second fold, when made, as shown in Fig. 4-

The bag will then be presented to a second, bottom fold forming means and the once folded bottom end thereof again folded so that the infolded face of the second bottom fold 18 is brought into Contact with the externally applied transverse stripe or stripes of adhesive 17 and secured thereby to the side of the bag. The externally applied second fold-securing adhesive stripe or stripes 17 may be applied before the said first bottom fold is made, e. g. at the second adhesive-applying station and the disposition of the adhesive stripes in relation to the unfolded bottom end of the bag tube will then be as shown in Fig. 10 or 1l.

Again alternatively, the externally applied stripe ofr adhesive 12 which secures the rst end fold Hap 14 to the bag walls may be widened sufficiently to extend beyond the inner edge of the rst fold ap and serve as an adhesive seal for the second formed end fold 1S in place of, or in addition to, the adhesive stripe 17.

Furthermore, in addition to the application of the second fold-securing stripe of adhesive 17 as above described, or instead of the said adhesive stripe 17, a transverse stripe of adhesive 19 may be applied to the external face of the first folded bottom ap 14 so as to be carried over with the second bottom fold into fold-securing contact with the wall 9b of the bag tube or with the adhesive stripe 17 if this is also used (see Fig. 12).

lt will readily be understood that the omission of the gusset fold forming operations from the above described procedure is all that is necessary to produce plain or at bags with double folded bottoms by the method of the present invention.

lf it is desired to produce bags with straight lip mouths and/ or without mouth flaps, the aforesaid marginal slots or notches 6 will be disposed entirely to one side of each transverse severing line of the bag tube so'that in each case the entire slot or notch lies in the fold area of the transversely folded to form the closed bottom of the bag. tube.

The method of the present invention may also be applied with advantage to the manufacture of substantially powderproof bags from individual blanks which are rst folded longitudinally into either a plain or gusset folded form of bag tube and the bottom end thereof thereafter transversely folded to form the closed bottom of the bag.

i claim:

l. A method of producing a tubular gusset folded Satchel bag with a folded bottom, comprising the steps of making the said bag tube from a web of bag-making material by folding the longitudinal margins of the said web across the centre part thereof, cutting away a portion of each longitudinal margin so that when the said bag tube is formed the openings left by the said cut away portions combine to form a transversely extending slot-like opening in the bottom end fold area of one of the sides of the said bag tube through which the internal Wall of the opposite side of the said bag tube is exposed, forming iirst yand second gusset folds longitudinally of the said bag tube during the formation thereof, applying adhesive to the inner face of the said web in order internally to seal the said rst formed gusset folds in the bottom end fold area of the said bag tube, shaping the said transverse opening so as to expose therethrough part of the face of each said second formed gusset fold, applying a stripe of adhesive to the formed bag tube along the entire length of the transverse edge of the said transverse opening formed in the bottom end fold area and in overlapping relation to the said edge so that the adhesive stripe is applied in part to the external wall of one side of the bag tube and in part to the exposed face of each said second formed gusset fold and internal Wall of the opposite side of the said bag tube, and transversely folding over the bottom end of the said bag tube along a line within said opening to cover the said transverse opening thereby bringing the inturned face of the said bottom fold into contact with the said stripe of adhesive thus to seal the bottom end fold of the said bag tube across substantially the entire Width thereof.

2. The method claimed in claim l, including the steps of providing the formed bag tube with a second bottom end fold and applying an additional stripe of adhesive to the external wall of the bag tube in the bottom and fold area thereof prior to completing the said second end fold and in order to secure the later to the bag tube.

3. A method of producing a tubular gusset folded satchel bag with a folded bottom end, comprising the steps of making the said bag tube from a web of bagmaking material by folding the longitudinal margins of the said web across the centre part thereof, cutting away a portion of each said longitudinal margin so that when the said bag tube is formed the openings left by the said cut away portions combine to form a transversely extending slot-like Opening in the bottom end fold area of one of the sides of the said bag tube through which the internal Wall of the opposite side of the bag tube is exposed, forming first and second gusset folds longitudinally of the said bag tube during the formation thereof, applying adhesive to the inner face of the said web in order to seal the said first formed gusset folds internally in the bottom and fold area of the said bag tube, shaping the said transverse opening so as to expose therethrough part of the face of each second formed gusset fold, applying a stripe of adhesive to that part of the bottom end of the said bag tube within said opening which forms the inturned face of the bottom end fold ilap, so that the said adhesive stripe is brought into contact with the external wall and exposed face of each said second formed gusset fold and internal wall of the bag tube along the entire length of the said opening in the bottom end fold area of the bag tube when the said bottom end iiap is folded over to form the first bottom end fold.

4. The method claimed in claim 3, including the steps of providing the formed bag tube with a second bottom end fold, and applying an additional stripe of adhesive to the external wall of one side of the said bag tube in the bottom end fold area thereof prior to completing the said second fold and in order to secure the latter to the said bag tube.

5. A method of producing a tubular gusset folded satchel bag with a folded bottom comprising the steps of making the said bag tube from a web of bag-making material by folding the longitudinal margins of the said web inwards across the centre part thereof, forming first and second longitudinal gusset folds in the said bag tube during the folding thereof7 cutting away a portion of each said longitudinal margins so that when the bag tube is formed the openings left by the said out away marginal portions combine to form an opening in the bottom end fold area of one of its sides through which the internal wall of the opposite side of the bag tube is exposed across substantially its entire wi th, applying adhesive to the inner face of the said web in order internally to seal the said rst formed gusset foids in the bottom end fold area of the bag tube7 and shaping the said opening formed in the said bottom end fold area so as to expose part of the face of each said second formed longitudinal gusset fold for contact with the adhesive subsequently applied to the bag tube in the bottom fold area thereof, applying adhesive to the formed bag tube in the bottom end fold area thereof and then transversely folding the bottom end of the said bag tube along a iine within said opening so that the adhesive lies beneath the said bottom fold and is so applied as to extend across the bag tube and at least in part in `Contact with the internal Wall of the bag tube along the entire length of *he opening through which the internal wall is exposed and secures the inturned face of the said bottom fold to both the internal and external walls of the bag tube, thereby to seal the bottom end fold of the formed bag across substantially the entire width thereof.

References Cited in the file of this patent UNITED STATES PATENTS 352,921 Harriss Nov. 23, 1886 1,010,833 West Dec. 5, 1911 1,027,168 Bartlett May 2l, 1912 1,265,270 Snyder May 7, 1918 

